Brace lock assembly for scaffolding

ABSTRACT

A brace lock assembly for mounting on a vertical post in a scaffolding system includes a brace-receiving stud and a threaded bolt fixed to the post in longitudinally spaced aligned relation, a locking member mounted on the stud and bolt for longitudinal reciprocal sliding movement relative to the post, the locking member having inner slot means cooperating with the stud and bolt for guiding the member in its movement and outer slot means cooperating with the stud to enable a brace to be mounted on the stud and, when mounted, to be locked thereon in respective reciprocal positions of the locking member, spring means mounted on the bolt, and nut means engaging the bolt and constraining the spring means for applying a force to the locking member, whereby the locking member is secured to the post for said movement relative to the post while being constrained against free movement by frictional drag.

United States Patent [1 1 Plough Feb. 18, 1975 BRACE LOCK ASSEMBLY FOR [57] ABSTRACT SCAFFOLDING [75] Inventor: Russell H. Plough, Chicago, Ill. A brace lock assembly for mounting on a vertical post in a scaffolding system includes a brace-receiving stud [73] Asslgnee f Corporation D65 Flames and a threaded bolt fixed to the post in longitudinally spaced aligned relation, a locking member mounted [22] Filed: Nov. 29, 1973 on the stud and bolt for longitudinal reciprocal sliding movement relative to the post, the locking member [211 App! 419921 having inner slot means cooperating with the stud and bolt for guiding the member in its movement and [52] U.S. Cl. 403/49, 182/179 outer slot means cooperating with the stud to enable a [5 l] Int. Cl. E04g 7/22 brace to be mounted on the stud and, when mounted. [58] Field of Search 182/178, 179; 403/49; to be locked thereon in respective reciprocal positions 151/38 of the locking member, spring means mounted on the bolt, and nut means engaging the bolt and constrain- [56] References Cited ing the spring means for applying a force to the lock- UNITED STATES PATENTS ing member, whereby the locking member is secured 3 017208 H1962 wyse 403/49 to the post for said movement relative to the post 3'122385 2/1964 403/49 while being constrained against free movement by 3,399,269 8/1968 Willox a v v l5l/38 frictional drag- 3,458.222 7/1969 Juculano 403/49 Primary Examiner-Reinaldo P. Machado Attorney, Agent, or Firm-Norman H. Gerlach 7 Claims, 5 Drawing Figures PATENTED 8|975 3.867. 043.

saw 10F 2 PATENTED FEB! 8 I975 .SHEBI 20F 2 BRACE LOCK ASSEMBLY FOR SCAFFOLDING BACKGROUND OF THE INVENTION an assembly of the type embodying a stud projecting from a vertical post and adapted to receive the apertured end of a cross-brace thereover, and a locking member mounted for reciprocal longitudinal movement relative to the post and constructed for cooperation with the stud to alternately enable a brace to be received on or removed from the stud, and prevent a brace received on the stud from being removed, in respective positions of the locking member.

Prior art brace lock assemblies of the foregoing type include no provision for holding the locking member out of the way while mounting one or more crossbraces on the stud during assembly of the scaffolding, or while removing the braces during disassembly. Moreover, the prior assemblies have other disadvantages. Thus, U.S. Pat. No. 3,017,208 discloses a brace lock assembly of the foregoing type, having no provision for securing its locking member out of the way during assembly and disassembly. As disclosed in subsequent U.S. Pat. No. 3,360,287, the structure of the earlier patent does not function consistently in its intended manner, and certain side flanges are necessary. The structure of the later patent likewise includes no provision for holding its locking member out of the way, and it also employs certain roll pins for retention of the locking member. The roll pins are relatively fragile and easily damaged by the cross-braces and in handling. Time, labor and material requirements necessarily increase when the foregoing problems are encountered. Other prior structures also suffer from deficiencies which increase the time and labor for assembly and disassembly, and/or increase the manufacturing and material requirements.

SUMMARY OF THE INVENTION The brace lock assembly of the invention is employed in a scaffolding system in combination with a post mounted in normal use with its longitudinal axis extending vertically. The brace lock assembly includes a stud fixed to the post and adapted to receive thereover the apertured end of an elongated cross-brace, a threaded bolt fixed to the post in longitudinally spaced aligned relation to the stud, a locking member mounted on the stud and the bolt for longitudinal reciprocal movement relative to the post, the locking member having inner and outer legs each having means defining a slot therein and the slots being aligned for inserting the stud through both of them and for inserting the bolt through at least the slot in the inner leg, the stud and the bolt cooperating with the slot means in the inner leg to guide the locking member in its movement, the legs being spaced apart to receive the end of at least one cross-brace over the stud and between the legs, the slot in the outer leg having an open end enabling reciprocation of the locking member between an unlocking position wherein the outer leg clears the stud to enable a cross-brace end to be received on or removed from the stud, and a locking position wherein the outer leg receives the stud in the slot thereof to prevent a crossbrace end received on the stud from being removed, seating means on the post adapted for sliding movement of the inner leg thereon during movement of the locking member, spring means mounted on the bolt and arranged for applying a radially inward force to one of the legs when constrained, and nut means threadedly engaging the boltfor constraining the spring means to apply such force, whereby the locking member is secured to the post for longitudinal reciprocal sliding movement relative to the post while being constrained against free movement by frictional drag.

In a preferred embodiment, the seating means comprise shoulders projecting from the post adjacent the inner ends of the stud and the bolt, adjacent ends of the locking member legs are joined by a reverse bend, and an inturned flange is provided on the opposite end of the inner leg and is adapted for making contact with the post to limit tilting movement of the locking member about a transverse axis.

In a further preferred embodiment, a stud and a bolt are secured at each end of the post, and they are so disposed that the ends of the post may be transposed in use. In such embodiment, the brace lock assembly preferably is provided in two different forms, one of which is employed at each end of the post.

The new brace lock assembly having a locking member constrained against free movement holds the locking member out of the way when the cross-braces are being mounted during assembly of a scaffold, and when the braces are being removed during disassembly. With no necessity to manipulate the locking member at the same time, both hands of a worker are available to handle the braces and other structure, thereby minimizing time and labor requirements. The assembly is easily and rapidly locked and unlocked by merely sliding the locking member down or up, as the case may be, without need for other adjustment of parts or tightening of nuts. When locked, the assembly is safeguarded against accidental displacement of the locking member.

The brace lock assembly is relatively simply and economically constructed of a minimum number of parts. It is especially rugged and durable, and, in particular, it resists damage from blows or other forces in handling and in use. The assembly employs but one movable part, which is held captive in use.

BRIEF DESCRIPTION OF THE DRAWINGS The attached drawings illustrate preferred embodiments of the invention, without limitation thereto. In the drawings, like elements are identified by like reference symbols in each of the views, and:

FIG. 1 is a broken perspective view ofa portion of a scaffold, illustrating cross-bracing structure embodying two forms of the brace lock assembly of the invention;

FIGS. 2 and 3 are enlarged broken front and side elevational views, respectively, of the brace lock assemblies of FIG. I secured to one of the posts of the scaffold, illustrating the locking members of the assemblies in their unlocking positions and showing in broken lines in FIG. 2 the ends of two cross-braces received on each of the studs of the assemblies;

FIG. 4 is an enlarged broken front elevational view of the structure illustrated in FIG. 2, with the brace ends shown in full lines, illustrating the locking members in their locking positions; and

FIG. 5 is an enlarged broken side elevational and vertical sectional view of the structure illustrated in FIG. 2, with the locking members shown in longitudinal section taken substantially centrally thereof and the brace ends shown in cross section, illustrating the locking members in their locking positions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 of the drawings, a scaffold 10 includes a frame 12 and cross-bracing structure 14 connected to the frame. The scaffold 10 is similar in its general construction and arrangement to the scaffold illustrated in U.S. Pat. No. 3,751,081, but employs new brace lock assemblies according to the invention. As in the patent, the scaffold 10 is useful for supporting loads, for platforming, and for other purposes where it is desirable to employ a scaffold having removable bracing.

The scaffold frame 12 in the illustrative structure includes a pair of spaced, parallel tubular posts or uprights 18 mounted in normal use with their longitudinal axes extending vertically. The posts 18 are joined by spaced parallel upper and lower tubular tie bars 20 which extend horizontally and transversely of the scaffold l and are welded to the posts at their opposite ends. When erected in a scaffolding system, a plurality of frames 12 are aligned and joined together by the cross-bracing structure 14.

The cross-bracing structure 14 includes an upper brace lock assembly 22 and a lower brace lock assembly 24 mounted on each post 18 respectively at the upper and lower ends thereof, and in longitudinal or vertical alignment. The structure also includes one or more cross-braces 26 having flattened opposite ends 28 connected to each of the lock assemblies 22 and 24. The cross-braces 26 are elongated members extending longitudinally of the scaffold l0, and they extend diagonally or are inclined between spaced pairs of posts 18 in successive frames 12, to provide the X-type of bracing. In the illustrative scaffold 10, the ends of two braces 26 are connected to each of the brace lock assemblies 22 and 24. Where the scaffolding terminates (not shown), only one brace 26 may be connected to each of the brace lock assemblies 22 and 24 on the end frame 12. As subsequently described, it is also within the scope of the invention to provide brace lock assemblies such as the assemblies 22 and 24 which accommodate a greater number of cross-braces 26, including cross-braces which extend horizontally.

The tie bars 20 are secured to the posts 18 adjacent to and spaced inwardly from the opposite ends 30 and 32 of the posts. The brace lock assemblies 22 and 24 are mounted at the respective upper and lower ends of the posts and adjacent to the tie bars 20, and are spaced inwardly from the tie bars to provide adequate clearance for locking and unlocking the assemblies.

Referring also to FIGS. 2-5, each of the brace lock assemblies 22 and 24 includes the combination of a stud 34 and a threaded bolt 36 all in longitudinal alignment and so arranged that in use, the ends 30 and 32 of the post 18 may be transposed. Each stud 34 includes a smooth cylindrical shank 38 and an integral enlarged head 40 forming a flat annular shoulder 42 adjacent one end of the stud. The stud is fixed on the surface of the post 18 by a weld 44 joining the head 40 to the post. The stud 34 extends radially outwardly from the post, and its shank 38 is adapted to receive thereover the apertured end 28 of a cross-brace 26. As illustrated in FIGS. 4 and 5, each of the flattened opposite ends 28 of each of the cross-braces 26 is provided with a circular attachment aperture 46 having a diameter slightly greater than that of the stud shank 38. The shank 38 is inserted through the apertures 46 of two cross-braces 26 in the structure illustrated, and may be inserted through the aperture 46 of a single cross-brace 26 at a terminal frame 12 in a scaffolding system.

Each bolt 36 includes a threaded cylindrical shank 48 and an integral enlarged head 50 forming an annular shoulder 52 adjacent one end of the stud. The head 50 is secured on the surface of the post 18 by a weld 54. In each instance, the bolt 36 is disposed in longitudinally spaced relation to its companion stud 34 and between the stud and the proximate extremity 30 or 32 of the post 18. The bolt 36 projects radially outwardly from the post 18 in alignment with the stud 34, in vertical planes.

The upper and lower brace lock assemblies 22 and 24 include respective locking members 56 and 58 mounted on a stud 34 and bolt 36 combination for longitudinal reciprocal movement relative to the post 18. Both of the locking members 56 and 58 are of generally U-shaped construction, preferably formed of a bent steel strip or the like, and each functions to hold one or more brace ends 28 captive on a stud 34. The locking members 56 and 58 differ in their respective lengthwise dimensions, for cooperation with the transposed relationship of the stud 34 and bolt 36 combinations at the upper and lower ends of the post 18. The upper locking member 56, employed in the upper brace lock assembly 22, includes a slotted relatively long inner leg 60, a bifurcated relatively short outer leg 62, a reverse bend or bight 64 integrally connecting the adjoining upper ends of the legs, and an inturned stabilizer flange 65 integral with the opposite lower end of the inner leg and extending substantially perpendicularly therefrom. The inner leg 60 is provided with a closed elongated slot 66 of width just slightly greater than the substantially equal diameters of the stud shank 38 and the bolt shank 48. In the illustrative embodiment, the length of the slot 66 is approximately twice the distance between the centers of the stud 34 and the bolt 36, for reasons which will appear.

The outer leg 62 includes two prongs 68 which define a slot 70 that is closed at its upper end and open at its lower end. The slot 70 has a width but slightly greater than the diameters of the stud shank 38 and the bolt shank 48, and a length greater than the distance between the outer sides of the shanks 38 and 48 but shorter than the length of the closed inner slot 66. The outer slot 70 has the same width as the inner slot 66, has its closed end in horizontal alignment with the upper end of the inner slot, and is aligned vertically or longitudinally with the inner slot.

The stud shank 38 and the bolt shank 48 are insertable through both of the aligned slots 66 and 70, as seen most clearly in FIGS. 4 and 5. The upper locking member 56 is mounted on the upper stud 34 and bolt 36 combination in this manner, with the inner surface of the inner leg 60 seated on the shoulders 42 and 52 and longitudinally slidable thereon. The stabilizer flange on the inner leg 60 is closely adjacent to and preferably contacts the surface of the post 18.

As thus mounted, the upper locking member 56 is reciprocally movable between an upper, unlocking position as illustrated in FIGS. 2 and 3, and a lower, locking position as illustrated in FIGS. 4 and 5. The locking member 56 is guided in its movement and retained on the post 18 by cooperation of the stud shank 38 and the bolt shank 48 with the walls of the closed slot 66 in the inner leg 60. In the unlocking position as illustrated in FIGS. 2 and 3, the outer leg 62 clears the stud shank 38 while yet receiving the bolt shank 48 in the slot 70 between its prongs 68. The spacing between the shanks 38 and 48 and the clearance between the stud shank 38 and the prongs 68 of the outer leg 62 are sufficient to enable the apertured ends 28 of the cross-braces 26 to be received over the stud shank 38 or removed therefrom, as seen from the broken line illustration in FIG. 2.

In the locking position of the upper locking member 56 as illustrated in FIGS. 4 and 5, both the bolt shank 48 and the stud shank 38 are received by the outer leg 62, in its slot 70 between its prongs 68. In this position, the prongs 68 overlie the cross-brace ends 28 for retaining them on the stud shank 38, between the inner leg 60 and the outer leg 62.

In the upper brace lock assembly 22, the bolt shank 48 extends through the slot 70 in the outer leg 62 at all times. The bolt shank extends outwardly for a distance sufficient to enable an annular washer 72, a coil compression spring 74, and a threaded nut 76 to be secured on the bolt shank 48, in that order and with the washer 72 seated on the outer surface of the outer leg 62. The spring 74 is arranged for applying a radially inward force to the locking member when constrained. The nut 76 threadedly engages the bolt shank 48 for constraining the spring 74 to apply such force. The washer 72 serves to transmit spring pressure directly to the outer leg 62 of the locking member 56 while facilitating sliding longitudinal movement thereof. The amount of force applied is determined by the degree to which the nut 76 is tightened against the spring 74.

The upper locking member 56 is secured to the post 18 in the foregoing manner for longitudinal reciprocal movement relative to the post, with the inner surface of the inner leg 60 sliding on the shoulders 42 and 52. The outer surface of the outer leg 62 slides on the inner surface of the washer 72. Owing to the pressure of the spring 74, the locking member 56 is constrained against free movement by frictional drag on its surfaces. It is contemplated that, in general, the nut 76 will be tightened to such an extent that the locking member 56 is movable by hand while being securely held against free movement both in the raised, unlocking position of FIGS. 2 and 3, and in the lowered, locking position of FIGS. 4 and S. The locking member 56 may be moved by application of hand pressure to its upper bend 64 or its lower flange 65. Alternatively, the nut 76 may be tightened to a greater extent, rendering it necessary to move the locking member 56 with a tool such as a hammer, and the bend 64 and the flange 65 provide striking surfaces for this purpose.

With the locking member 56 in the raised, unlocking position, a workman may attach or remove the crossbrace ends 28 without need for holding or manipulating the locking member or adjusting the nut 76. With the locking member 56 in the lowered, locking position, the cross-brace ends 28 are prevented from being removed from the stud shank 38. The locking member 56 then is not susceptible to being raised to the unlocking position unintentionally as a result of vibrations, and is not readily raised by accidental contacts with other members.

The lower locking member 58, similarly to the upper locking member 56, includes a long inner leg 78 having an elongated closed slot 80 therein, a short outer leg 82 having an open-ended slot 84 therein and vertically aligned with the closed slot 80, the slots 80 and 84 also having closed upper ends in horizontal alignment, a reverse bend 86 integrally connecting the adjacent upper ends of the legs 78 and 82, and an integral inturned stabilizer flange 88 at the opposite, lower end of the inner leg 78. The slots 80 and 84 have equal widths, which are but slightly greater than the diameters of the stud shank 38 and the bolt shank 48. The closed slot 80 in the inner leg 78 has a length somewhat greater than twice the distance between the centers of the stud shank 38 and the bolt shank 48, and is correspondingly longer than the closed slot 66 in the upper locking member 56. The length of the open-ended slot 84 in the outer leg 82 of the lower locking member 58 is such as to receive only the stud shank 38, and not the bolt shank 48.

The lower locking member 58 is mounted on the lower stud 34 and bolt 36 combination, with the stud shank 38 and the bolt shank 48 extending through the closed slot 80 in the inner leg 78, and the inner surface of the inner leg 78 seated on the shoulders 42 and 52 for longitudinal reciprocal sliding movement thereon. The locking member 58 is movable from an upper, unlocking position illustrated in FIGS. 2 and 3 to a lower, locking position illustrated in FIGS. 4 and 5. In the unlocking position, the outer leg 82 is raised or withdrawn to clear the stud shank 38, for mounting the ends 28 of two cross braces 26 on the shank. In the locking position, the stud shank 38 is received within the slot 84 of the outer leg 82 and between the prongs 90 thereof. The prongs and adjacent portions of the outer leg 82 overlie the brace ends 28 for retaining them on the stud shank 38, between the inner leg 78 and the outer leg 82. The walls of the closed slot 80 serve to guide and limit the lower locking member 58 in its reciprocal movement, as with the corresponding structure in the upper locking member 56.

A washer 72, a spring 74, and a nut 76 are secured on the shank 48 of the bolt 36 in the lower brace lock assembly 24, as in the upper brace lock assembly 22. However, in the lower brace lock assembly 24, the bolt 36 does not extend through the outer leg 82, and the washer 72 is seated on the outer surface of the inner leg 78. A radially inwardly directed compression spring force is applied directly to the inner leg 78 rather than to the outer leg 72. The spacing of the bolt 36 and the elements mounted thereon is such as to permit the mounting of the brace ends 28 on the stud shank 38 without interference.

The inner leg 78 of the lower locking member 58 thus is mounted so that its inner surface is slidable on the shoulders 42 and 52, and its outer surface is slidable on the inner surface of the washer 72. The locking member 58 in the lower assembly 24, like the locking member 56 in the upper assembly 22, is secured to the post 18 for longitudinal reciprocal sliding movement relative to the post while being constrained against free movement by frictional drag on its surfaces. As with the upper assembly 22, the lower assembly 24 may have its nut 76 adjusted to enable the locking member 58 to be moved up and down by hand pressure or by a greater force, either of which may be applied to the bend 86 or to the stabilizer flange 88. Each of the upper and lower locking members 56 and 58 can be moved individually into its upper locking position and will remain there while a workman attaches or removes the cross-braces 26. Each of the locking members 56 and 58 can be moved individually into its lower, locking position when the braces 26 to be secured by the locking member are in place on the corresponding stud shank 38.

The stabilizer flanges 65 and 88 of the locking members 56 and 58 serve to limit tilting movement of the locking members about a transverse or horizontal axis. Thus, referring particularly to FIG. 5, any force tending to pull the upper end of either locking member outwardly from the post 18 about a transverse axis below the point of application of the force, is resisted by contact of the stabilizer flange 65 or 88 with the post. The flange 88 on the locking member 58 in the lower assembly 24 is the more advantageous for this purpose, inasmuch as there is no direct restraint on the outer leg 82 and the adjacent part of the inner leg 78, and these parts conceivably might be sprung outwardly with sufficient force, to release the cross-brace ends 28 from the stud shank 38. Also, if desired, the stud shank 38 may be lengthened to safeguard against the foregoing possibility. It will be noted that in the upper assembly 22, the application of the spring force directly to the outer leg 62 increases the resistance to any force tending to spread apart the inner and outer legs 60 and 62. As previously noted, the stabilizer flanges 65 and 88 also provide surfaces for the application of force to move the locking members 56 and 58 upwardly, and furthermore, they assist in guiding the locking members 56 and 58 in their reciprocal movement.

The bends 64 and 86 in the locking members 56 and 58 in the illustrative embodiments are dimensioned to separate the legs of the locking members for a distance sufficient to accommodate two flattened cross-brace ends 28 therebetween, with substantially no more play or looseness than results from variations in the thickness of the flattened ends 28 as encountered in practice. It is desirable that such play be minimized, to make the scaffold 10 as rigid as possible, in particular, to limit the sidewise movement of the cross-braces 26. As noted above, the terminal or end frames 12 may be joined by but one cross-brace 26 at each brace lock assembly 22 and 24. The space or play resulting from the absence of one of the normally two cross-braces 26 may be taken up if desired by placing a washer on each of the shanks 38, next to each single brace end 28.

It will be apparent that, in an alternative construction (not shown), the locking member bends 64 and 86 may have greater depth, to increase the spacing between the legs ofthe locking members 56 and 58, thereby accommodating additional cross brace ends 28. Thus, for example, the aforementioned U.S. Pat. No. 3,751,081, illustrates a scaffolding having both diagonal and horizontal braces, with four brace ends being connected at one point on a post. Similarly, both diagonal and horizontal cross braces may be secured together by the present lock assemblies 22 and 24, with the locking member bends 64 and 86 dimensioned to accommodate four brace ends 28 mounted on the shanks 38 between the locking member legs.

lt will be apparent, further, that the brace lock assemblies 22 and 24 of the invention are equally useful for securing braces which extend transversely of the scaffold 10, as well as longitudinally thereof. In particular, such transverse braces may extend between posts in the direction of the tie bars 20.

While preferred embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein within the spirit and scope of the invention. It is intended that such changes and modifications be included within the scope of the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a scaffolding system, in combination:

a post mounted in normal use with its longitudinal axis extending vertically; and

a brace lock assembly comprising:

a stud fixedly secured to said post and projecting radially outwardly therefrom, said stud being adapted to receive thereover the apertured end of an elongated cross-brace,

a threaded bolt fixedly secured to said post in longitudinally spaced relation to said stud and projecting radially outwardly from said post in alignment with said stud,

a locking member mounted on said stud and'said bolt for longitudinal reciprocal movement relative to said post,

said locking member having inner and outer legs each having means defining a slot therein and said slots being aligned for inserting said stud through both of them and for inserting said bolt through at least the slot in the inner leg, said stud and said bolt cooperating with said slot means in said inner leg to guide said locking member in said movement,

said legs being spaced apart a distance sufficient to receive the end of at least one cross-brace over said stud and between said legs, said slot in said outer leg having an open end which enables reciprocation of said locking member between an unlocking positionwherein the outer leg clears said stud to enable a cross-brace end to be received on or removed from the stud, and a locking position wherein the outer leg receives the stud in the slot thereof to prevent a cross-brace end received on thestud from being removed,

seating means on said post adapted for sliding move ment of said inner leg thereon during said locking member movement,

spring means mounted on said bolt and arranged for applying a radially inward force to one of said legs when constrained, and

nut means threadedly engaging said bolt for constraining said spring means to apply said force, whereby said locking member is secured to said post for longitudinal reciprocal sliding movement relative to the post while being constrained against free movement by frictional drag.

2. A scaffolding system as claimed in claim 1 and wherein said seating means comprise shoulders projecting from said post adjacent the inner ends of said stud and said bolt, wherein adjacent ends of said locking member legs are joined by a reverse bend, and including an inturned flange on the opposite end of the inner leg and adapted for making contact with said post to limit tilting movement of said locking member about a transverse axis.

3. A scaffolding system as claimed in claim 1 and including a brace lock assembly as defined therein at each end of said post, said bolt in each assembly being disposed between said stud therein and the proximal extremity of the post.

4. A scaffolding system as claimed in claim 3 and wherein said locking member in each assembly in use is movable up and down respectively for unlocking and locking purposes.

5. A scaffolding system as claimed in claim 4 and wherein in the brace lock assembly at the normally upper end of the post the locking member is constructed for inserting the bolt through both of the slots in the locking member legs and the spring means is arranged for applying a force to the outer leg, and in the brace lock assembly at the normally lower end of the post the locking member is constructed for inserting the bolt only through the slot in the inner leg of the locking member and the spring means is arranged for applying a force to the inner leg.

6. In a scaffolding system, in combination:

a post mounted in normal use with its longitudinal axis extending vertically; and

upper and lower brace lock assemblies each comprisa stud having a shank and an enlarged head forming a shoulder with the shank and which is welded on the surface of said post, said stud projecting radially outwardly from said post and being adapted to receive over its shank the apertured end of an elongated cross-brace,

a threaded bolt having a shank and an enlarged head forming a shoulder with the shank and which is welded on the surface of said post in longitudinally spaced relation to said stud and between the stud and the proximal extremity of the post, said bolt projecting radially outwardly from said post in alignment with said stud,

a locking member mounted on said stud and said bolt for longitudinal reciprocal movement relative to said post, said locking member having parallel inner and outer legs joined at their upper ends by a reverse bend and said inner leg sliding on said shoulders during said locking member movement,

said legs each having means defining a slot therein and said slots being aligned for inserting said stud 10. shank through both of them and for inserting said bolt shank through the slot in the inner leg, said slot means in said inner leg defining a closed slot for retention of said locking member on said stud and said bolt and cooperating therewith to guide said locking member in said movement,

said legs being spaced apart a distance sufficient to receive the end of at least one cross-brace over said stud shank and between said legs, said slot in said outer leg having an open lower end which enables reciprocation of said locking member between an upper unlocking position wherein the outer leg clears said stud shank to enable a cross-brace end to be received on or removed from the stud, and a lower locking position wherein the outer leg receives the stud shank in the slot thereof to prevent a cross-brace end received on the stud from being removed,

spring means mounted on said bolt shank and arranged for applying a radially inward force to said locking member when constrained, and nut means threadedly engaging said bolt shank for constraining said spring means to apply said force;

said upper brace lock assembly having its locking member constructed for inserting its bolt shank through both of the slots in the locking member legs and having its spring means arranged for applying a force to the outer leg,

and said lower brace lock assembly having its locking member constructed for inserting its bolt shank only through the slot in the inner leg of the locking member and having its spring means arranged for applying a force to the inner leg,

whereby said locking members are secured to said post for longitudinal reciprocal sliding movement relative to the post while being constrained against free movement by frictional drag.

7. A scaffolding system as claimed in claim 6 and including an inturned flange on the lower end of the inner leg of each locking member and adapted for making contact with said post to limit tilting movement of the locking member about a transverse axis. 

1. In a scaffolding system, in combination: a post mounted in normal use with its longitudinal axis extending vertically; and a brace lock assembly comprising: a stud fixedly secured to said post and projecting radially outwardly therefrom, said stud being adapted to receive thereover the apertured end of an elongated cross-brace, a threaded bolt fixedly secured to said post in longitudinally spaced relation to said stud and projecting radially outwardly from said post in alignment with said stud, a locking member mounted on said stud and said bolt for longitudinal reciprocal movement relative to said post, said locking member having inner and outer legs each having means defining a slot therein and said slots being aligned for inserting said stud through both of them and for inserting said bolt through at least the slot in the inner leg, said stud and said bolt cooperating with said slot means in said inner leg to guide said locking member in said movement, said legs being spaced apart a distance sufficient to receive the end of at least one cross-brace over said stud and between said legs, said slot in said outer leg having an open end which enables reciprocation of said locking member between an unlocking position wherein the outer leg clears said stud to enable a cross-brace end to be received on or removed from the stud, and a locking position wherein the outer leg receives the stud in the slot thereof to prevent a cross-brace end received on the stud from being removed, seating means on said post adapted for sliding movement of said inner leg thereon during said locking member movement, spring means mounted on said bolt and arranged for applying a radially inward force to one of said legs when constrained, and nut means threadedly engaging said bolt for constraining said spring means to apply said force, whereby said lOcking member is secured to said post for longitudinal reciprocal sliding movement relative to the post while being constrained against free movement by frictional drag.
 2. A scaffolding system as claimed in claim 1 and wherein said seating means comprise shoulders projecting from said post adjacent the inner ends of said stud and said bolt, wherein adjacent ends of said locking member legs are joined by a reverse bend, and including an inturned flange on the opposite end of the inner leg and adapted for making contact with said post to limit tilting movement of said locking member about a transverse axis.
 3. A scaffolding system as claimed in claim 1 and including a brace lock assembly as defined therein at each end of said post, said bolt in each assembly being disposed between said stud therein and the proximal extremity of the post.
 4. A scaffolding system as claimed in claim 3 and wherein said locking member in each assembly in use is movable up and down respectively for unlocking and locking purposes.
 5. A scaffolding system as claimed in claim 4 and wherein in the brace lock assembly at the normally upper end of the post the locking member is constructed for inserting the bolt through both of the slots in the locking member legs and the spring means is arranged for applying a force to the outer leg, and in the brace lock assembly at the normally lower end of the post the locking member is constructed for inserting the bolt only through the slot in the inner leg of the locking member and the spring means is arranged for applying a force to the inner leg.
 6. In a scaffolding system, in combination: a post mounted in normal use with its longitudinal axis extending vertically; and upper and lower brace lock assemblies each comprising: a stud having a shank and an enlarged head forming a shoulder with the shank and which is welded on the surface of said post, said stud projecting radially outwardly from said post and being adapted to receive over its shank the apertured end of an elongated cross-brace, a threaded bolt having a shank and an enlarged head forming a shoulder with the shank and which is welded on the surface of said post in longitudinally spaced relation to said stud and between the stud and the proximal extremity of the post, said bolt projecting radially outwardly from said post in alignment with said stud, a locking member mounted on said stud and said bolt for longitudinal reciprocal movement relative to said post, said locking member having parallel inner and outer legs joined at their upper ends by a reverse bend and said inner leg sliding on said shoulders during said locking member movement, said legs each having means defining a slot therein and said slots being aligned for inserting said stud shank through both of them and for inserting said bolt shank through the slot in the inner leg, said slot means in said inner leg defining a closed slot for retention of said locking member on said stud and said bolt and cooperating therewith to guide said locking member in said movement, said legs being spaced apart a distance sufficient to receive the end of at least one cross-brace over said stud shank and between said legs, said slot in said outer leg having an open lower end which enables reciprocation of said locking member between an upper unlocking position wherein the outer leg clears said stud shank to enable a cross-brace end to be received on or removed from the stud, and a lower locking position wherein the outer leg receives the stud shank in the slot thereof to prevent a cross-brace end received on the stud from being removed, spring means mounted on said bolt shank and arranged for applying a radially inward force to said locking member when constrained, and nut means threadedly engaging said bolt shank for constraining said spring means to apply said force; said upper brace lock assembly having its locking member constructed for inserting its bolt shank through both oF the slots in the locking member legs and having its spring means arranged for applying a force to the outer leg, and said lower brace lock assembly having its locking member constructed for inserting its bolt shank only through the slot in the inner leg of the locking member and having its spring means arranged for applying a force to the inner leg, whereby said locking members are secured to said post for longitudinal reciprocal sliding movement relative to the post while being constrained against free movement by frictional drag.
 7. A scaffolding system as claimed in claim 6 and including an inturned flange on the lower end of the inner leg of each locking member and adapted for making contact with said post to limit tilting movement of the locking member about a transverse axis. 